1. Field of the Invention
The present invention relates to a character input system having a plurality of input elements disposed in a two dimensional manner.
2. Description of the Prior Art
When a memorandum-recording function is added to very small electronic apparatus such as business card-sized calculators or wrist watches, it is difficult to dispose a sufficient number of touch-activated character input devices such as character keys necessary for a variety of characters (26 in the case of the alphabet) because of the limited area of the operation panel on such electronic units.
As one of solutions for overcoming this difficulty, it may be thought to use nine input devices in total disposed in a square configuration of, for instance, 3.times.3. This arrangement provides two kinds of input methods. The first method involves inputting a character by describing its shape on an operation panel which is composed of input devices such as key switches. This method is disclosed in U.S. Pat. No. 3,909,785. The second method involves inputting a character by operating, in a predetermined sequence, only those input devices in positions corresponding to the characteristic and unique points which shape the character such as the character's starting point, its corners (turning points) and finishing point. Although this second input method offers a faster input speed than the first input method, it involves numerous input operations and still has the drawback of a slow input speed.
Further, in Swiss Patent No. 533,332 and Japanese Patent Application Laid-Open No. 54-4527, there is disclosed a plurality of key switches arranged in 3.times.5 and 3.times.3, respectively, so that the key switches represent various segments of characters or numerals. In these disclosure, the key switches do not produce character codes, but produce signals corresponding to segments of actual characters. In these cases, it is necessary that many segments of a character are inputted. As a result, these methods still involve many input operations and accordingly such an inputting operation requires a substantially long time.